From what I see the only crew stats you can change without changing the game mechanics is changing the speed at which the crew moves or how many plasma/ammo they can carry or both combined with some smart juggling e.g. 2 speed steps = +1 plasma. This way neither speed or plasma become too maxed out.
If you introduce crew jobs it would be like the "Faster than Light" game or similar which would increase complexity & game lag since crews still must be used to supply all the power. That's why I'm saying if you change to cumulative stats system and get rid of the need to use the crew as power supplier it would open the way to real world stuff and a lot of other possibilities (even those not yet available to any other games). But I understand this is kind of late at this point and would require a lot of work to change it. You decide.
Edit: On that note if you do it you could as well change all room parts to an open room design based on floor parts only and use smart bitmaps for display the differences. I guess weapons, thrusters will remain the same, though.
